What was HyperCard?

CompileIt! Manual - This is a PDF of the manual to CompileIt!, a HyperCard stack that allows you to write HyperCard command plug-ins that access the Mac's system API and let you do everything any Mac programmer could do.

HyperTalk Reference - This is a PDF containing screen shots of most of the pages of the HyperTalk Reference stack that came with HyperCard 2.4.

MediaTalk Reference - This is an HTML-dump of the MediaTalk documentation included with Oracle Media Objects.